Mass hysteria attack rates in children and adolescents: a meta-analysis

OBJECTIVES: There are few systematic assessments of mass hysteria (MH) attack rates (ARs) in adolescents and children. The study aim was to assess the ARs of MH in this population. METHODS: We used a meta-analysis to systematically review studies and assess ARs. RESULTS: The reviewed studies included 32,887 participants, of which 2968 were children and adolescents with a history of MH. Twenty-eight studies were included, of which 22 (78.6%) had high to moderate methodological quality. The pooled AR of MH was 9.8% (95% confidence interval [CI] 6.3, 14.0). Of MH studies between 2010 and 2020, 78.6% were conducted between 2010 and 2014. ARs were higher between 2010 and 2014 (10.3%) than between 2015 and 2020 (8.1%). Regarding population characteristics, the AR in girls was 2.43 (95% CI 1.70, 3.46) times higher than in boys. Most studies were on primary school students (46.4%), who showed the highest AR (15.4%). Of six trigger factors, water pollution showed the highest AR (16.3%). ARs were higher in rural areas (11.1%) than in urban areas (5.6%). CONCLUSIONS: MH in children and adolescents seems prevalent and shows some epidemiological characteristics. These findings may assist governments to control and prevent MH epidemics among children and adolescents.